Teses / dissertações sobre o tema "Thermal risk assessment"

By deploying Fibre-Optic Distributed Temperature Sensing, this thesis aims to improve understanding of the influences of drought-induced low flows, surface water warmings, shifts between up- and downwelling flows, and hydroclimatological controls on surface water and streambed temperature dynamics. First, the potential drought impacts on surface water and streambed temperature patterns of lowland streams are quantified. Second, high-resolution streambed sediments temperature distributions following altered groundwater-surface water exchange under distinct increased surface water temperatures are analysed. Third, the hyporheic refuge hypothesis is tested at high spatio-temporal resolution under different groundwater-surface water exchange and warming scenarios. Fourth, high-resolution seasonal variability in streambed sediments temperature distributions of a forested stream reach is quantified. The main outcomes are: 1) surface water and streambed temperature patterns in co-evolved vegetated artificial lowland streams varied with water level; 2) the direction of groundwater-surface water exchange impacted on the transfer of thermal stress into gravel streambeds under different warming scenarios; 3) alterations of the direction of groundwater-surface water exchange influenced the potential of the hyporheic zone of gravel streambeds to provide a refuge under warming; 4) seasonal variations of streambed temperatures in a forested stream reach are primarily driven by hydroclimatological conditions.

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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Mavris, Dimitri N.; Committee Member: German, Brian J.; Committee Member: Osburg, Jan; Committee Member: Ruffin, Stephen M.; Committee Member: Schrage, Daniel P.. Part of the SMARTech Electronic Thesis and Dissertation Collection.

A comunicação de riscos vem se tornando uma atividade indispensável à formação de uma opinião pública que avalie de uma forma racional e equilibrada a construção de novas centrais nucleares em países que utilizam ou pretendam utilizar esta tecnologia. Favorecidos pela tradição de considerar que a ciência é suficiente para convencer qualquer cidadão ao provar o domínio sobre o processo, as organizações nucleares organizam-se para tal empreendimento dando preferência às explicações técnicas, às minuciosidades relacionadas ao risco destas instalações. Entre os cidadãos comuns, no entanto, a percepção do risco é subjetiva e, portanto não é nivelada com a percepção que tais esforços de comunicação de risco tentam propor. Algumas vezes tal percepção é subestimada e, mais frequentemente, exagerada. A maximização ou até a extrapolação desta da percepção de risco é incentivada pela mídia sensacionalista e movimentos de defesa do meio ambiente. Este trabalho estuda a percepção e a considera como relevante neste esforço de promover a aceitação das usinas termonucleares propondo abandonar o discurso tradicional de riscos e aumentar os esforços em comunicar benefícios, de forma similar à propostas de marketing para produtos, serviços ou, como neste caso, a venda de uma idéia. Há uma revisão bibliográfica de conceitos de risco, de comunicação de riscos e de marketing. Em seguida, um estudo prático com base em centenas de entrevistas com estudantes de diversos níveis da região metropolitana da grande São Paulo. O estudo traz importantes informações sobre a forma como tais pessoas percebem as usinas termonucleares, seus benefícios e quais os atores que as influenciam positiva ou negativamente neste processo.
Public acceptance of the nuclear based electricity generation depends on many variables that can be affected by circumstances and interests, which although seemingly not close to the issue, can strongly influence the final outcome. Explicit or consented positions assumed by opinion makers and some segments of society are subject to episodic waves of interaction through the media and they permeate to the public in a process that is very complex to be fully understood. The modeling of such process is a very complicated undertaking, and gives no assurance of practical results concerning to what, how and who, should be given prominence in the interactions with the media and the general public. In this context, the risk communication has assumed a leading role and, as a consequence, most of the interaction with the public has been done with both defensive language and content. This study has tried a simple and practical approach to the problem, in such a way as to gather some interesting subsidies to treat this issue in a different way. The basic assumption is that in a similar way as individuals base their decision to acquire a new good or service on a \"intuitive\" cost-benefit judgment, society (as a collection of individuals) also manifest their acceptance (or not) with respect to industrial installations and undertakings by comparing risks and benefits according to their perception. An exploratory survey was carried out in a few high schools, colleges and MBA courses in the state of Sâo Paulo, Brazil. A first part was aimed to catch and understand the public perception of. (a) the Intrinsic value of the electric energy, (b) the need to universalize the access to electricity, (c) nuclear plants, (d) the acceptance deficit of nuclear power as compared to other sources of energy, (e) the benefits a nuclear plant can bring, (f) who does and who does not deserves credibility to speak about nuclear plants. The second part was addressed to grasp a picture of more relevant distortions concerned to the public perception of a nuclear power plant risks. The analysis of the survey results and the utilization of a model inspired by the marketing way of value communication suggest a different approach to the communication with the public concerning to nuclear power plants. In this proposal, named Value Strategy, a matrix of risks vs. benefits is segmented in nine regions, where the central region corresponds to the current situation and the others show the possible (hypothetical) future situations after the installation of a nuclear power plant. There are three favorable regions, inductives of acceptance and three unfavorable ones, or routed to rejection. Based on the understanding of the targeted public, as partially revealed by the survey, different nuances can be emphasized in the communication to maximize its effect, without any detour to ethical behavior. Results also disclose various complementary subsidies to help the communication strategy, mainly regarded to the communication agents and to the more effective argument areas according to factors such as: sex, age ranges and educational level.

L'Elastographie par onde de cisaillement ou ShearWave Elastography (SWE) est une technique échographique de caractérisation tissulaire permettant de mesurer in vivo les propriétés élastiques des tissus vivants. Le champ d’application de ce mode est large et a prouvé son utilité dans plusieurs domaines, mais il n’inclut pas le domaine obstétrical malgré son intérêt clinique potentiel. Ce travail de thèse s’inscrit dans l’évaluation des effets sanitaires de la SWE dans le domaine de la périnatalité. Il s’appuie sur deux articles publiés et un article soumis dans des revues à comité de lecture international. Dans un premier temps, une revue de la littérature scientifique a permis de décrire les principes physiques fondamentaux des ultrasons, les différentes variantes des méthodes élastographiques, et surtout la technique SWE développé par la société Supersonic Imagine (SSI), le CHU Estaing à Clermont Ferrand ayant acquis un échographe de cette marque (modèle AIXPLORER®). Dans une seconde partie, en s’appuyant sur la méthode d’Evaluation Quantitative de Risque Sanitaire (méthode EQRS), nous avons tenté d’identifier les effets et les risques sanitaires associés aux ultrasons, d’une manière générale, et plus spécifiquement liés à l’utilisation de techniques d’élastographie sur le foetus [Article 1]. Deux effets biologiques des ultrasons ont été identifiés : un effet mécanique et un effet thermique. La radiation énergétique de l’onde de « push » a été considéré comme le facteur de risque potentiel. Dans un troisième temps, nous avons initié l’étude ELASTORISK-I afin d’évaluer l’effet thermique de cette technique élastographique. Cette étude étant éthiquement inenvisageable chez des foetus humains, elle a été réalisée en deux parties : une étude sur un tissu biologique porcin [Article 2] puis sur un phantom physique homogène (Casper-1) représentatif des tissus foetaux [Article 3].La première partie de l’Etude ELASTORISK-I (article 2, chapitre 3) reposait sur une mesure comparative par caméra infrarouge, en conditions expérimentales identiques, de l’échauffement lié aux techniques échographiques (SWE, Doppler pulsé et B-mode) sur un tissu biologique de porcin. L’objectif était de quantifier cet échauffement et de démontrer l'intérêt et la pertinence de la thermographie infrarouge, qui est une technique non invasive de mesure de la température de surface en champ complet. Cette étude a montré que la thermographie infrarouge pourrait être une approche expérimentale complémentaire aux thermocouples qui sont actuellement la référence. Les résultats ont révèlé que l’échauffement le plus important était associé à la SWE.La deuxième partie d’ELATORISK-I (article 3, chapitre 4) a été dans la continuité de notre réflexion sur la quantification et l’évaluation, dans une approche comparative, de l’échauffement lié aux différentes modalités échographique (SWE, Doppler pulsé et mode-B) en utilisant des thermocouples placés dans un phantom imitant le tissu humain (Casper-1). Les résultats de cette étude ont confirmé les données obtenues en thermographie.Ce travail de thèse a apporté des connaissances sur l’effets biologiques de l’utilisation de SWE et a contribué à initier le débat au sein de la communauté scientifique sur le sujet des risques sanitaires potentiels de l’utilisation SWE en imagerie foetale. Il ouvre le champ à d’autres expérimentations, en particulier en phantom hétérogène intégrant des « tissus osseux » (casper-2) et incite investiguer les effets mécaniques (déplacements créés par l’onde de « push » = étude ELASTORISK-II (en cours))
Shear wave elastography (SWE) is an ultrasound technique used to measure in vivo the elastic properties of tissues. The area of application of this mode is widespread and has proved its relevance in several areas, but it does not include the obstetrical field regardless of its potential clinical interest. This thesis research is part of the evaluation of the health effects of SWE in the field of perinatal care. It is based on two published articles and one article submitted in international peer-reviewed journals. First, a review of the scientific literature described the fundamental physical principles of ultrasound, the different variants of elastographic methods, and especially, the SWE technique developed by Supersonic Imagine (SSI), the CHU Estaing in Clermont Ferrand having acquired an ultrasound scanner from this brand (AIXPLORER® model). In the second part, using the Quantitative Health Risk Assessment method (QHRA method), we reviewed the literature with a view to identifying the health effects and risks of ultrasound associates in general and more specifically those related to the use of elastography techniques on the foetus[Article 1]. Two biological effects of ultrasound were identified: a mechanical effect and a thermal effect. The energetic radiation of the push wave being identified as the potential risk factor. In a third part, we initiated the ELASTORISK-I study to evaluate the thermal effect of this elastographic technique. As this study was ethically unthinkable in human fetuses, it was carried out in two parts: a study on a porcine biological tissue [Article 2] and then on a homogeneous physical phantom (Casper-1) representative of the fetal tissues [Article 3].The first part of ELASTORISK-I (article 2, chapter 3) is a comparative measurement by infrared camera, using identical experimental conditions, of the heating related to ultrasound techniques (SWE, pulsed Doppler and B-mode) on a biological tissue of a porcine. The objective was to quantify this heating and to demonstrate the interest and relevance of infrared thermography, which is a non-invasive technique for measuring surface temperature in the full field. This study shows that infrared thermography could be an experimental approach complementary to the thermocouples that are currently the reference. The results demonstrate that the most significant warm-up is associated with SWE.The second part of ELATORISK-I (article 3, chapter 4) is in the continuation of our reflection on the quantification and evaluation, in a comparative approach, of the heating related to the different ultrasound modalities (SWE, pulsed Doppler and mode-B) by using thermocouples placed in a phantom imitating human tissue (Casper-1). These results confirm the data obtained in thermography. This study has provided us with knowledge about the biological effects of SWE use and has helped to initiate debate within the scientific community about the potential health risks of SWE use in fetal imaging. It opens the field to other experiments, in particular by heterogeneous phantom combining bone (casper-2) and encourages the investigation of mechanical effects (displacements created by the "push" wave =

A tendência em ampliar o uso das tecnologias com aproveitamento da energia solar no setor residencial traz para os profissionais da área de projeto novos desafios que é o de reestruturar seus modelos de concepção e desenvolvimento de projetos a fim de garantir o comportamento em uso e a eficiência dos sistemas construtivos seguros. O Modelo conceitual de identificação e qualificação de risco proposto foi elaborado a partir da pesquisa de investigação e de desenvolvimento experimental. Foram considerados aspectos relativos às demandas de segurança em uso, construção do conhecimento a partir da sistemografia e a forma de integração desses saberes em um único sistema. O desenvolvimento experimental ocorreu durante o processo de projeto, produção, montagem, uso e operação de um protótipo denominado Ekó House. A metodologia aplicada envolveu quatro fases: Fase 1 - Exploratória - com pesquisas bibliográficas (as tecnologias, normas e práticas de projeto; Fase 2 - Definições - com a escolha da base teórica de apoio ao modelo; Fase 3 - Desenvolvimento - proposições e experimentos e Fase 4 - Teste e consolidação. Para validar o modelo aplicou-se a validação por generalização analítica, ou seja, expandir e generalizar a teoria. O modelo proposto, inovador no âmbito da sistemografia, apoiou-se na Teoria do Sistema Geral: teoria da modelização proposta por LE MOIGNE. Essa teoria trabalha com sistemas complexos e se apoia em processadores, são eles: de operação, informação e decisão que condicionam a integração sistêmica do projeto. Verificou-se durante a aplicação do modelo que ele estimula o aprofundamento das análises das soluções de projeto, quando: a)Identifica e formaliza conceitos que suportam o desenvolvimento das soluções nos diversos sistemas; xv b)Facilita a compreensão e síntese das múltiplas informações que precisam ser compatibilizadas no projeto; c)Formaliza um único principio \"segurança do usuário\" para a lógica de concepção e desenvolvimento de projeto; d)Organiza e permite que se priorizem as informações técnicas [fabricantes e normas];e)Facilita o entendimento por meio de informações as ações de organização e coordenação dos sistemas no espaço e de sua relação com as funcionalidades, uso e estética; e f)Fomenta a busca de soluções mais adequadas a segurança do usuário. Sendo assim, o teste do modelo validou a hipótese. Ele contribui como ferramenta guia de aprimoramento do processo de projeto.
The increasing use of solar energy technologies in the residential sector brings new challenges to professionals who work in the field of design, such as the need to restructure their mindset regarding to the conception and to the development of design, in order to ensure the performance and the efficiency of safe building systems. In this context, this thesis main goal is to propose a conceptual model for the identification and qualification of risk within residential architecture that uses solar energy technologies based on systemography. It\'s an investigative and experimental research, considering aspects related to: meet the demands of safety in use, the knowledge construction and how those could be managed. The experimental development was carried out during the process of design, production, assembly, use and operation of a prototype named Ekó House. The applied method has encompassed four stages: 1) Exploratory - bibliographic research about technologies, codes, rules and design practices; 2) Definitions - the choice of the theoretical basis to ground the model; 3) Development - propositions and experiments and 4) Proofing and consolidation. In order to verify the model it was carried out a test wherewith is possible to perform a validation by analytical generalization, that is, expand and generalize the theory. The proposed model, which represents an innovation in sistemography field, was based on LE MOIGNES\'s Systemic Theory. This Theory enabled the implementation in complex systems, using information, decision and operating processors which condition the design systemic integration. The results obtained by the research show that the model: a) incorporates knowledge, thus, being helpful along the decision-making process; b) eases the understanding and the overview of the diverse information needed by the design; c) formalizes a logic of design conception and development; d) xvii organizes and prioritizes the design technical recommendations [rules and manufacturers]; e) is able to promote an interference in the system\'s organization and coordination in space and also in its relation to functionality and aesthetics; it also f) guides the use of more suitable configurations to the design development. The model presents itself as a tool that is capable of reducing misuse of standards, conflicts between building systems, Technologies and architecture, as well as design failures that compromise safety in use.

Hur kan livscykelanalyser bistå riskvärderingen vid val av åtgärdsmetod? I det här examensarbetet undersöktes hur resultaten från livscykelanalyser kan användas i beslutstödsverktyget SAMLA för förorenade områden för att bistå val av åtgärdsmetod vid Finspångs centraltvätt. Examensarbetet har genomförts i samarbete med Structor Miljö Öst AB. Livscykelanalyser har utförts för två olika typer av åtgärdsmetoder in situ, stimulerad anaerob reduktiv deklorering samt elektrisk konduktiv uppvärmning. Tidigare studier har visat att olika livscykelanalysmetoder ger olika resultat. Även den här studien bekräftar det. Därför bör inte resultat från olika metoder jämföras. Livscykelanalyser kompletterar SAMLA för förorenade områden väl. De procentuella förhållandena beräknades mellan åtgärdsmetodernas miljö- och klimatpåverkan. I värderingssteget i SAMLA bedöms åtgärdsalternativens påverkan i jämförelse med nollalternativet. En bedömning gjordes av respektive åtgärdsalternativ och korrigering av förhållandet mellan metoderna utfördes genom att samma procentuella förhållande som beräknats fram för miljöbelastningen respektive klimatpåverkan beräknades för värderingspoängen. Med stöd av livscykelanalyser samt riskvärdering bör efterbehandlingsmetoden stimulerad anaerob reduktiv deklorering väljas för Finspångs centraltvätt.
How can life cycle analyzes assist the risk assessment when choosing a remediation method? In this thesis, it was investigated how the results from life cycle analyzes can be used in the decision support tool SAMLA for contaminated sites to assist in the choice of remediation method at Finspång's Centraltvätt. The thesis has been carried out in collaboration with Structor Miljö Öst AB. Life cycle analyzes have been performed for two different types of in situ remediation methods, Enhanced Reductive Dechlorination and Electrical Conductive Heating. Previous studies have shown that different life cycle analysis methods lead to different results. This study also confirms this. Therefore, results from different methods should not be compared. Life cycle analyzes complement SAMLA for contaminated sites. The percentage ratios were calculated between the remediation methods' environmental and climate impact. In the valuation step in SAMLA, the impact of the remediation alternatives is assessed in comparison with the no action alternative. An assessment was made of the respectively remediation alternatives and a correction of the relationship between the methods was performed by calculating the same percentage ratio that was calculated for the valuation points of the environmental and climate impact. With the support of the life cycle analysis and the risk assessment the remediation method Enhanced Reductive Dechlorination should be chosen for Finspång's Centraltvätt.

Les énergies fossiles jouent un rôle fondamental dans l'économie, la société et la politique. Il existe différentes énergies renouvelables pouvant présenter une alternative telles le solaire, l'éolien, l'hydro-électrique ou encore la biomasse. Parmi ces énergies renouvelables, la biomasse est la seule source de carbone pouvant être utilisée pour la production de carburants, produits chimiques ou matériaux. Parmi les produits chimiques issus de la biomasse, la production de molécules plateformes comme l'acide lévulinique (AL) et ses esters est une voie attractive. Ces molécules peuvent être obtenues par solvolyse de la cellulose ou hémicellulose. L’hydrogénation de ces molécules plateformes conduit à la production de γ-valerolactone (GVL) qui peut aussi être considéré comme une molécule plateforme. Pour favoriser le passage à l'échelle industrielle et trouver les conditions opératoires optimales vis-à-vis de la sécurité et des coûts de production, les questions suivantes doivent être répondues : - Quel est le risque thermique de cette réaction d' hydrogénation? ; - Quel réactif doit-on utiliser : AL ou ses esters? ; - Afin de favoriser l’intégration énergétique, comment mesurer les enthalpies de réactions? Dans un premier temps l'évaluation des risques thermiques pour l' hydrogénation de l’acide lévulinique en GVL catalysée par Ru/C dans l'eau a été effectuée. Un modèle cinétique simple incluant un bilan énergétique en condition pseudo-adiabatique a été développé pour estimer les constantes cinétiques et les paramètres de risque thermique. Par cette étude, il a été possible de déterminer des conditions opératoires sûres pour ce système afin de prévenir les emballements thermiques. Dans un deuxième temps, une approche structure-réactivité a été effectuée en utilisant le concept de relation linéaire de l’énergie libre, à savoir l’équation de Taft. Cette équation a été utilisée pour l'hydrogénation de l'acide lévulinique et de ses esters en GVL catalysée par Ru/C. Le GVL a été utilisé comme solvant pour solubiliser les différents réactifs : AL, lévulinate de méthyle (LM), d'éthyle (LE) et de n-butyle (LB). Il a été démontré que la première étape cinétique, à savoir l'hydrogénation de LA, LM, LE ou LB en leurs intermédiaires et la cinétique de la deuxième étape, à savoir la cyclisation suivent l'équation de Taft. Les effets polaires et stériques ont été évalués et il a été montré que l'effet polaire gouverne ces étapes réactionnelles. La dernière partie de cette thèse consiste à estimer les enthalpies de réaction par calorimétrie. L'estimation de ces constantes thermodynamiques peut s'avérer complexe parce que le GVL est utilisé comme solvant et qu'il n'y a pas d'informations sur les intermédiaires. L’hydrogénation du lévulinate de méthyle a été sélectionnée pour cette étude. Une méthode utilisant les données calorimétriques et analyse chimique a permis d’évaluer l'enthalpie réactionnelle globale et les enthalpies des 2 réactions consécutives. Il a été montré que l'enthalpie globale a une valeur de -51.5 kJ/mol de GVL produits montrant que le système est dans sa globalité exothermique. L’enthalpie d'hydrogénation a été estimée à -58-66 kJ/mol de LM consommé et celle de cyclisation à +7,16 kJ/mol de GVL produits
Fossil energy plays a fondamental role in the economy, society and politics. Till now, different renewable energy are explored to be an alternative for energy supply, such as wind, solar, hydro­ and biomass energy. Among these renewable energy, biomass is regarded as the organic carbon source which can be applied for production of fuels, chemicals or materials. Among the bio-based chemicals, production of platform molecules such as levulinic acid (LA) and its esters is one of attractive way for biomass valorization. LA and its esters can be obtained through hydrolysis and alcoholysis of cellulose or hemicellulose. By further hydrogenation, γ-valerolactone (GVL) is produced and it is also regarded as a platform molecule for further upgrading to biofuels and chemicals with wide application. To scale-up the hydrogenation reaction and to find the optimum operating conditions towards safety and cost, the following questions must be answered : - What is the thermal risk of this reaction? ; - Which starting materials to choose (LA or esters)? ; - For a better energy integration of this process, how to measure the reaction enthalpies? Herein, at first, thermal risk assessment for hydrogenation of LA to GVL catalyzed by Ru/C in water was performed. A simplified kinetic model including energy balance under near-adiabatic conditions was developed to estimate the kinetic constants and thermal risk parameters of this reaction system. Through this thermal risk assessment, it was possible to know the safe operation conditions for this reaction system, i.e., preventing the risk of thermal runaway. Secondly, a structure-reactivity approach was carried out using the concept of Linear Free Energy Relationships (LFER). i.e., Taft equation. The Taft equation (LFER) was applied to hydrogenation of LA and its corresponding esters to GVL catalyzed over Ru/C. GVL was used as a solvent to allow the solubility of the different reactants, namely, LA, methyl levulinate (ML), ethyl levulinate (EL) and n-butyl levulinate (BL). It was demonstrated that the kinetics of the first step, i.e., hydrogenation of LA, ML, EL or BL to the corresponding intermediates and the kinetics of the second step, i.e., ring-closure follow Taft equation. The polar and steric effect of the substituents were evaluated, and it is shown that polar effect governs the kinetics of both reaction steps. Thirdly, the estimation of reaction enthalpies by calorimetry experiments was done. The estimation of such thermodynamic constants by using different thermodynamic models can be hazardous, because in this study GVL was used as a solvent and there are no data concerning the intermediates. Hydrogenation of methyl levulinate (ML) to GVL catalyzed over Ru/C was selected for this study. A method which links calorimetry measurement with composition analysis was developed to determine the reaction enthalpies of the overall reaction and two consecutive steps. It was found that the overall reaction enthalpy was -51.5 kJ/mol of GVL produced, which indicates that the reaction for production of GVL from ML is exothermic. The reaction enthalpy for the first hydrogenation step was calculated to be -58.66 kJ/mol of ML consumed, and for the reaction enthalpy for the second ring-closure step was calculated to be +7.16 kJ/mol of GVL produced

Dans le contexte du secteur de l’aviation, qui pose des défis importants en raison de la complexité et des normes strictes en matière de carburant, notre proposition de recherche revêt une pertinence particulière. Nous visons à développer une approche intégrée qui valorise pleinement la biomasse lignocellulosique en carburéacteurs, contribuant ainsi au développement durable de la société. La biomasse lignocellulosique est une ressource renouvelable qui peut être utilisée comme matière première pour produire des matériaux et des produits chimiques de grande valeur, tels que le kérosène. Ce type de valorisation de la biomasse comprend de nombreuses étapes de transformation, pour lesquelles la cinétique et le risque thermique de la réaction chimique ne sont pas forcément connus. Ce travail se concentre sur un composé spécifique : le lévulinate de butyle (BL). Ce composé peut être obtenu à partir de la biomasse lignocellulosique et peut être transformé en gamma-valérolactone (GVL) par hydrogénation. Le GVL est une molécule de plateforme vitale qui peut servir de matière première pour produire des substituts aux combustibles fossiles comme l’essence, le diesel et les carburéacteurs. Les principaux objectifs de cette recherche sont les suivants : 1) Développer un modèle cinétique robuste et fiable pour l’hydrogénation BL afin de produire du GVL. Ici, nous cherchons à développer expérimentalement un modèle cinétique dans différents modes de fonctionnement thermiques, c’est-à-dire isotherme, isopéribolique et adiabatique. Ce type de modèle permet non seulement de prédire la cinétique et le débit de chaleur correspondant, mais aussi d’évaluer le risque thermique lié à la réaction chimique. Les expériences de développement de ce modèle cinétique ont été réalisées dans le réacteur calorimétrique Mettler-Toledo RC1. 2) La valorisation complète de la biomasse lignocellulosique vise l’échelle industrielle. Par conséquent, la production continue de GVL à partir de BL doit être évaluée. En ce sens, nous avons étudié la stabilité thermique de la production continue de GVL à partir de BL dans un réacteur CSTR (réacteur à cuve agitée continue). 3) L’un des aspects intrigants de notre recherche est l’utilisation potentielle du lévulinate de butyle (BL) comme additif pour carburants. Nous avons mené une évaluation approfondie de l’adéquation du BL en tant qu’additif de kérosène, dans le but de comprendre comment son ajout affecte le rendement de combustion et les limites de fonctionnement dans une chambre de combustion de turbine à gaz. Les résultats obtenus concernant le modèle cinétique ont montré que les modèles non compétitifs de Langmuir-Hinshelwood prédisent les données expérimentales de concentration et de température pour l’hydrogénation des BL avec une bonne précision. L’analyse du risque thermique, liée à l’hydrogénation BL, a montré que l’énergie libérée lors de la réaction est relativement faible, ΔH_{hyd} = -35.28 kJ/mol +/- 1.00 kJ/mol, et par la suite l’étude de stabilité thermique a montré que pour des valeurs de Ua > 1500 W/m³/K dans un réacteur continu, le risque d’instabilités thermiques est faible. L’évaluation du BL en tant qu’additif de kérosène a montré que l’ajout de 20 % de BL dans le kérosène ne modifie pas de manière significative les propriétés physiques, ni l’efficacité de la combustion, ni les limites de fonctionnement dans les conditions de fonctionnement prises en compte lors de l’évaluation de la combustion
In the context of the aviation sector, which poses significant challenges due to the complexity and stringent standards of fuel, our research proposal gains particular relevance. We aim to develop an integrated approach that fully valorizes lignocellulosic biomass into jet fuels, thereby contributing to the sustainable development of society. Lignocellulosic biomass is a renewable resource that can be used as feedstock to produce high-value materials and chemicals, such as jet fuel. This type of biomass valorization includes many transformation steps, for which the kinetics and the thermal risk of the chemical reaction are not necessarily known. This work focuses on a specific compound: butyl levulinate (BL). This compound can be obtained from lignocellulosic biomass and can be transformed into gamma-valerolactone (GVL) via hydrogenation. The GVL is a vital platform molecule that can serve as a feedstock to produce substitutes for fossil fuels like gasoline, diesel, and jet fuels. The main objectives of this research are: 1) To develop a robust and reliable kinetic model for BL hydrogenation to produce GVL. Here, we seek to develop a kinetic model experimentally in different thermal modes of operation, i.e., isothermal, isoperibolic, and adiabatic. This model type not only predicts kinetics and the corresponding heat-flow rate but also allows the assessment of the thermal risk related to the chemical reaction. The experiments for developing this kinetic model were performed in the calorimeter reactor Mettler-Toledo RC1. 2) The complete valorization of lignocellulosic biomass targets the industrial scale. Therefore, the continuous production of GVL from BL should be assessed. In that sense, we studied the thermal stability of the continuous production of GVL from BL in a CSTR reactor (continuous stirred tank reactor). 3) One of the intriguing aspects of our research is the potential use of butyl levulinate (BL) as a fuels additive. We have conducted a thorough assessment of the suitability of BL as a kerosene additive, aiming to understand how its addition affects the combustion efficiency and operating limits in a gas turbine combustion chamber. The results obtained concerning the kinetic model showed that the Non-Competitive Langmuir-Hinshelwood models predict the experimental data of concentration and temperature for BL hydrogenation with good accuracy. The thermal risk analysis, linked to BL hydrogenation, showed that the energy released during the reaction is relatively low, ΔH_{hyd} = -35.28 kJ/mol +/- 1.00 kJ/mol, and subsequently the thermal stability study showed that for values of Ua > 1500 W/m³/K in a continuous reactor, the risk of thermal instabilities is low. The evaluation of BL as a kerosene additive showed that adding up to 20% of BL into Kerosene does not significantly change the physical properties, neither the combustion efficiency nor the operating limits in the operating conditions considered during the combustion assessment
En el contexto del sector de la aviación, que plantea importantes retos debido a la complejidad y a los estrictos estándares de combustible, nuestra propuesta de investigación cobra especial relevancia. Nuestro objetivo es desarrollar un enfoque integrado que valorice plenamente labiomasa lignocelulósica en combustibles para aviones, contribuyendo así al desarrollo sostenible de la sociedad. La biomasa lignocelulósica es un recurso renovable que se puede utilizar como materia prima para producir materiales y productos químicos de alto valor, como el combustible para aviones. Este tipo de valorización de la biomasa incluye muchas etapas de transformación, para las cuales no necesariamente se conoce la cinética y el riesgo térmico de la reacción química. Este trabajo se centra en un compuesto específico: el levulinato de butilo (BL). Este compuesto se puede obtener a partir de biomasa lignocelulósica y se puede transformar en gamma-valerolactona (GVL) mediante hidrogenación. El GVL es una molécula plataforma vital que puede servir como materia prima para producir sustitutos de combustibles fósiles como la gasolina, el diésel y los combustibles para aviones. Los principales objetivos de esta investigación son: 1. Desarrollar un modelo cinético robusto y fiable para la hidrogenación de BL para producir GVL. Aquí, buscamos desarrollar un modelo cinético experimentalmente en diferentesmodos de operación térmica, es decir, isotérmico, isoperibólico y adiabático. Este tipo de modelo no solo predice la cinética y el flujo de calor correspondiente, sino que también permite evaluar el riesgo térmico relacionado con la reacción química. Los experimentos para el desarrollo de este modelo cinético se realizaron en el reactor calorímetro Mettler-Toledo RC1. 2. La valorización completa de la biomasa lignocelulósica se dirige a la escala industrial. Por lo tanto, debe evaluarse la producción continua de GVL a partir de BL. En ese sentido, estudiamos la estabilidad térmica de la producción continua de GVL a partir de BL en un reactor CSTR (reactor continuo de tanque agitado). 3. Uno de los aspectos intrigantes de nuestra investigación es el potencial uso del levulinato de butilo (BL) como aditivo de combustibles. Hemos llevado a cabo una evaluación exhaustiva de la idoneidad del BL como aditivo de queroseno, con el objetivo de comprender cómo su adición afecta la eficiencia de la combustión y los límites de funcionamiento en una cámara de combustión de turbina de gas. Los resultados obtenidos en relación con el modelo cinético mostraron que los modelos no competitivos de Langmuir-Hinshelwood predicen los datos experimentales de concentración y temperatura para la hidrogenación de BL con buena precisión. El análisis de riesgo térmico, vinculado a la hidrogenación BL, mostró que la energía liberada durante la reacción es relativamente baja, ΔH_{hyd} = -35.28 kJ/mol +/- 1.00 kJ/mol, y posteriormente el estudio de estabilidad térmica mostró que para valores de Ua > 1500 W/m ³/K en un reactor continuo, el riesgo de inestabilidades térmicas es bajo. La evaluación del BL como aditivo de queroseno mostró que la adición de hasta un 20% de BL al queroseno no cambia significativamente las propiedades físicas, ni la eficiencia de la combustión ni los límites de funcionamiento en las condiciones de funcionamiento consideradas durante la evaluación de la combustión

Cette étude traite du vieillissement des ouvrages en pierres calcaires en interaction avec leur environnement, en se basant à la fois sur la caractérisation des matériaux et des conditions climatiques locales. L’objectif de cette thèse est d’étudier le rôle des conditions climatiques sur la dégradation des pierres par une estimation quantitative du poids des différents processus physiques de dégradation : gel-dégel, condensation and dilatations hygro-thermiques empêchées. Deux sites majeurs ont été sélectionnés : le Château de Chambord en France et le site d’Al-Namrud en Irak, qui est une ancienne capitale assyrienne datant de 1280 BC. Les matériaux français étudiés sont le tuffeau et la pierre de Richemont, qui a été abondamment utilisée comme pierre de substitution durant les restaurations du 20ème siècle. Les matériaux irakiens utilisés sont issus de prélèvements sur des pierres d’origines altérées, des pierres d’origine saines, ainsi que la pierre candidate pour la restauration du site. L’approche choisie pour l’estimation du risque d’endommagement commence par la réalisation d’une campagne expérimentale de caractérisation multi-physiques et multi-échelles des pierres calcaires utilisées à Chambord, ajouté à la collecte des données météorologiques à Chambord grâce à une station et des mesures dans la pierre. L’estimation du risque d’endommagement est obtenue en combinant l’utilisation des données climatiques et de la caractérisation des matériaux, grâce au calcul de l’impact des différents processus physiques de dégradation, qui a nécessité plusieurs développements méthodologiques. La méthodologie proposée pour l’estimation du risque d’endommagement est ensuite appliquée au site d’Al-Namrud. Finalement, un carnet de santé numérique préliminaire du plus édifiant monument d’Al-Namrud – la Ziggurat – est réalisé pour son diagnostic de durabilité
This study deals with the ageing of limestone structures as a result of the interaction with their environment. It is based on the characterization of both the material and the local climatic conditions. The objective of this thesis is to study the role of climatic conditions in the degradation of stone by quantitative estimation of the weight of the different physical weathering processes: freezing-thawing, condensation and restrained hygro-thermal dilations. Two major historic sites were selected: the Château of Chambord in France and the site of Al-Nimrud City in Iraq, an ancient Assyrian capital, built in 1280 BCE. The French materials studied are tuffeau and Richemont stone, extensively used as a substitute for tuffeau restoration during part of the 20th century. The Iraqi materials studied are samples cored in situ in original weathered stones, original healthy stones, and the stone that could be used as a substitute for restoration. The approach chosen for damage risk assessment starts by the realization of a multiphysics and multiscale experimental characterization campaign of the limestone used at Chambord, added to the collection of meteorological data at Chambord thanks to a weather station supplemented by situ stone measurements. The damage risk assessment is obtained by the combined use of climate data and material characterization, through the calculation of the impact of thedifferent physical weathering processes, which required some methodological developments. The proposed damage risk assessment methodology is then applied to Al-Nimrud site. Finally, a preliminary digital health record of the most prominent monument of Al-Nimrud - the Al-Ziggurat - is carried out to diagnose its durability

碩士
淡江大學
化學工程學系
88
In recent years, the transportation of hazardous materials has been a great concern of both the proper authorities and the general public in Taiwan. Transport accidents occur during the transport and storage of hazardous hydrocarbons. Frequently such accidents result in fires, explosions, and toxic releases. Fire is more likely than explosion where there is a loss of containment of a flammable material. In addition to fires and explosions, the loss of containment of toxic chemicals from a tank may give rise to a large toxic gas cloud or may pollute water supplies. Three types of chemical tank trucks pertaining to thermal risk assessment were studied in this thesis, namely, (1) gasoline (2) methanol, and (3) ethylene oxide. Gasoline tank truck is dual-compartment, and oval-shaped. We developed computer models to simulate the thermal response of the gasoline tank trunk exposed to solar heating for extended periods of time as well as the computations of accidental discharge mass and efflux time. Methanol tank truck is single-compartment, and oval-shaped. We developed computer models to simulate the thermal response of the methanol tank trunk exposed to solar heating for extended periods of time as well as pool-fire exposure. Ethylene oxide tank truck is insulated, and round-shaped. We presented an inherently safe concept in designing an ethylene oxide tank truck. And then, we developed computer models to simulate the thermal response of the ethylene oxide tank trunk exposed to solar heating for extended periods of time as well as external fire exposure. Additionally, safety aspects, including static-electricity control, relief valve design and standard operating procedure (SOP) on loading, were discussed.

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the Degree of Master of Science in Engineering, 2016
Previously undermined areas pose a significant challenge to mining by opencast due to the risk of sinkhole occurrence. In order to optimise reserve utilisation as well as safeguard personnel and equipment there was need to develop a “Sinkhole Prediction Model” to assist in the prediction of areas prone to sinkhole formation. The aim of this research therefore was to develop a “Sinkhole prediction tool” with a view to pre-identifying areas of potential sinkhole hazard to inform better controls to assist in mining these areas safely. This was done utilising the current Hill (1996) caving height method culminating in the development of a hazard index model dividing the mining zones into high and low hazard. These areas were colour coded Red (High hazard) and Green (Low Hazard). The “Sinkhole Prediction Model” evolved to include over hundred sinkhole incidences that were statistically analysed to firm up on the robustness of the Prediction Model capabilities. The Hill (1996) caving height formula was discounted after the statistical analysis indicated that a good prediction model lies in the interrogation of site specific data. The outcome of the work conducted in this research report indicated a 97% correlation between the refined “Sinkhole Prediction Model” and the actual sinkhole occurrence at the Anglo American case study area (Mine X). Various refinements inclusive of lithological assessments, blast and drilling reconciliations as well as the implementation of the roughening up quality audits led to the implementation of a robust sinkhole management process that has managed to consistently assist in safeguarding equipment and personnel thus allowing for coal extraction optimisation in areas that could have been written off due to the sinkhole hazard. This risk can only be eliminated by mining the areas with the sinkhole risk. Currently the method is being impacted by significant roughening up cost incurred in a drive to make the areas safe to allow for coal extraction. The roughening up process on average costs R3.5 million per sinkhole and is a function of the number of sinkholes found, which translates to an equivalent cost of R7 / sales tonne. The current sinkhole prediction model being employed in deficient in that it cannot pinpoint the actual location of the void in the area previously undermined by bord and pillar and this is a great limitation of this report. Various geophysical techniques were pursued to assist in the precise identification of the actual sinkhole spatially. This process was aimed to reduce the roughening up cost (entire block stabilisation) as opposed to targeted sinkhole excavation and stabilisation. This process proved futile as the void identification systems are highly incapable of identifying the voids / iv sinkholes spatially (x, y and z coordinates) to assist targeted sinkhole treatment as a result of the following:  System inability to penetrate areas comprised of highly conductive strata such as clays.  Inability to distinguish between the underground voids and geological anomalies such as dykes.  Not suitable for penetrating wet strata.  Impacted by noise interference from mining machinery. The major result of this research is the establishment of a site specific “Sinkhole Prediction Model” that can generate hazard plans in real time thus informing the management on areas associated with a potential sinkhole hazard. The hazard plans can be generated timely and decisions made to facilitate safe coal extraction in areas of high sinkhole hazard. This has culminated in a robust sinkhole management process within the group that has managed to eliminate the risk of personnel and equipment exposure at Mine X. The roughening up process is accepted as the primary sinkhole mitigation or rehabilitation process with the need to work towards reducing the roughening up costs through development of the tool capable of precisely identifying the voids routinely to facilitate targeted rehabilitation. Significant research is required in this area as the mining environment is comprised of strata that currently cannot support the use of real time void identification to facilitate targeted void identification and rehabilitation. There is also merit in the future to formulate the database capable of assisting in the prediction of sinkholes in the Witbank coalfield as well as assist in robust management of mining boundaries across the different mining houses. The system implemented at Mine X is currently being deployed to other operations in the group where modification will be made to match the site specific conditions. Future research into understanding the sinkhole occurrence dynamics is quite crucial if targeted rehabilitation is to be achieved for cost reduction and mining sustainability. A combination of the understanding of the sinkhole occurrence driving mechanisms in conjunction with use of modelling packages such as ELFEN (a hybrid Modelling) tool will go a long way in enhancing the development of precise sinkhole prediction point in space.

1.Hazards are the prime cause of occupational health, safety and environmental problems. Identification of hazards and assessment of risk associated with them is an important practise to reduce accidents and production breakdowns. Hazard Identification Risk Assessment (HIRA) is a process of identifying the hazards and segregating them by characterizing their probability and severity which helps evaluating possible consequences. The conventional process for conducting HIRA is limited to hazards which can cause harm to the people. In 21st century the developed technology has resulted in transparent administration and stringent regulations which bought great importance to environment, property and reputation. The four factors are equally important so an integrated methodology is developed to cover hazards which may cause damage to property, environment and reputation along with people. The hazards identified in this process will be more accurate resulting a safer and productive work place. Coke Oven Battery- 6 Complex of Rourkela Steel Plant deals with hazardous operations which are resulted as high risk area in past 2 years. The purpose of this project is to develop a new methodology for Hazard Identification and Risk Assessment and use it for identifying and analysing the risks in the complex. The Battery complex is dived in to 5 departments Coal Handling, Battery Proper, Heating, Coke Dry Cooling Plant, Coke Handling and using the developed process all possible activities in the above departments are analysed and control measures for various health, safety and environmental risks are suggested. 2.Air pollution is the most important environmental concern associated with any Coal Fired Power plants in India. Coal is the prime fuel in the energy sector and it accounts for 70% of electrical power in India and continues to play a major role. Coal combustion emits huge amounts of harmful gases into environment and is also responsible for health problems and global climate change. Prediction of pollutant concentrations in the plant vicinity is essential to have an impact assessment of the power plant over the environment surrounding it. In the view of this, current project work focuses on air dispersion modelling of pollutants namely Sulfur dioxide (SO2) and Oxides of Nitrogen (NOx) released from a stack of selected power plant using coal as fuel. The results obtained from the modelling are used to determine the affected areas in the plant surroundings. In the current project air dispersion modelling is done using the software AERMOD.

Indiana University-Purdue University Indianapolis (IUPUI)
Lithium-ion batteries are widely used for portable electronics due to high energy density, mature processing technology and reduced cost. However, their applications are somewhat limited by safety concerns. The lithium-ion battery users will take risks in burn or explosion which results from some internal components failure. So, a practical method is required urgently to find out the failures in early time. In this thesis, a new method based on temperature difference between internal point and surface (TDIS) of the battery is developed to detect the thermal failure especially the thermal runaway in early time. A lumped simple thermal model of a lithium-ion battery is developed based on TDIS. Heat transfer coefficients and heat capacity are determined from simultaneous measurements of the surface temperature and the internal temperature in cyclic constant current charging/discharging test. A look-up table of heating power in lithium ion battery is developed based on the lumped model and cyclic charging/discharging experimental results in normal operating condition. A failure detector is also built based on TDIS and reference heating power curve from the look-up table to detect aberrant heating power and bad parameters in transfer function of the lumped model. The TDIS method and TDIS detector is validated to be effective in thermal runaway detection in a thermal runway experiment. In the validation of thermal runway test, the system can find the abnormal heat generation before thermal runaway happens by detecting both abnormal heating power generation and parameter change in transfer function of thermal model of lithium ion batteries. The result of validation is compatible with the expectation of detector design. A simple and applicable detector is developed for lithium ion battery catastrophic failure detection.

Indiana University-Purdue University Indianapolis (IUPUI)
Heat generation is a major safety concern in the design and development of Li ion batteries (LIBs) for large scale applications, such as electric vehicles. The total heat generation in LIBs includes entropic heat, enthalpy, reaction heat, and heat of mixing. The main objective of this study is to investigate the influence of heat of mixing on the LIBs and to understand whether it is necessary to consider the heat of mixing during the design and development of LIBs. In the previous research, Thomas and Newman derived methods to compute heat of mixing in LIB cells. Their results show that the heat of mixing cannot be neglected in comparison with the other heat sources at 2 C rate. In this study, the heat of mixing in different materials, porosity, particle sizes, and charging/discharging rate was investigated. A COMSOL mathematical model was built to simulate the heat generation of LIBs. The LIB model was based on Newman’s model. LiMn2O4 and LiCoO2 were applied as the cathode materials, and LiC6 was applied as the anode material. The results of heat of mixing were compared with the other heat sources to investigate the weight of heat of mixing in the total heat generation. The heat of mixing in cathode is smaller than the heat of mixing in anode, because of the diffusivity of LiCoO2 is 1 ×10-13 m2/s, which is larger than LiC6's diffusivity 2.52 × 10-14 m2/s. In the comparison, the heat of mixing is not as much as the irreversible heat and reversible heat, but it still cannot be neglected. Finally, a special situation will be discussed, which is the heat of mixing under the relaxation status. For instance, after the drivers turn off their vehicles, the entropy, ix enthalpy and reaction heat in LIBs will stop generating, but the heat will still be generated due to the release of heat of mixing. Therefore, it is meaningful to investigate to see if this process has significant influence on the safety and cycle life of LIBs.

The nuclear industry has long relied upon bounding parametric analyses in predicting the safety margins of reactor designs undergoing design-basis accidents. These methods have been known to return highly-conservative results, limiting the operating conditions of the reactor. The Best-Estimate Plus Uncertainty (BEPU) method using a modernized version of the Code-Scaling, Applicability, and Uncertainty (CSAU) methodology has been applied to more accurately predict the safety margins of the Oregon State University Advanced Plant Experiment (APEX) facility experiencing a Loss-of-Feedwater Accident (LOFA). The statistical advantages of the Bayesian paradigm of probability was utilized to incorporate prior knowledge when determining the analysis required to justify the safety margins. RELAP5 Mod 3.3 was used to accurately predict the thermal-hydraulics of a primary Feed-and-Bleed response to the accident using assumptions to accompany the lumped-parameter calculation approach. A novel coupling of thermal-hydraulic and statistical software was accomplished using the Symbolic Nuclear Analysis Package (SNAP). Uncertainty in Peak Cladding Temperature (PCT) was calculated at the 95/95 probability/confidence levels under a series of four separate sensitivity studies.
Graduation date: 2013